Magneto drive



F. D. HOWE. MAGNEIO DRIVE. APPLICATION FILED MAY 16, I918.

I .P ma Ap r.18, 1922.

' U TEI rRANK D. flown-or, ouYArrosA r'ALLs, oHro, AssieNoa, 13Y EsNn AssIe NrriN'rs, 'ro INTERNATIONAL H RvnsTEncoMrAN a CORPORATION or EW ansnY.

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To all whom it may concern: V

Be it known that I, FRANK D. HOWE, a citizen of the United States, residing at Cuyahoga Falls, in the county of Summlt and State of Ohio, have invented certain new-anduseful Improvements in Magneto Drives, of which the following is a full, clear, and'exact specification. v

This invention relates to couplings for driving shafts and is particularly adapted for useon magnetos.

The object of the invention is to provide a driving means for magneto ,shaftswh'ereby the shaft of the magneto may be retarded or. completely stopped for an instant and then be driven forward with a sudden impulse. This is particularly useful in starting an internal combustion engine running on a magneto where the low speed of the armature shaft of the magneto when directly driven will not give a sufficiently hot spark to ignite the charge in the cylinder.

- Another object is to provide means for holding the retarding device out of operation so that the armature is continuously driven by thedriving shaft.

Another object is to provide a coupling means which does not require that the armature shaft of the magneto and the driving shaft be inperfect adjustment, but which will automatically adjust itself for small variations therein.

Another object is to providea device having the foregoing advantages and which is at the same time of neat appearance and which can be economically manufactured.

These and other objects are accomplished by my invention which comprises a driving shaft and a driven shaft substantially in alignment, yieldable means connecting the two shafts and a springpressed roller adapted to retard the driven shaft.

Referring now to the drawing in which likereference numerals refer to like parts throughout,-

Figure 1 is a side elevation of my invention applied to a magneto;

Fig. 2 is an end elevation of the same; and

Fig. 3 is the same as Fig. 2 but showing a modification.

My invention comprises a magneto 1O having an armature shaft 11,'which I shall also call a driven shaft, and the driving shaft 12, the axes of these two shafts being in substantial alignment. The armature shaft 11 .added.

Specification of Letters Patent. Patefit d A i 1 8 19 22 Application filed May 16,1918. SerialNo. 234,970. l I

. and the driving have at their .7

the driving shaft. The face plate 14: carg,

ries a pin 17 whichis connected to theother pin 15 by means of a spring or other resilient means 18. 'Up onithe edge of the face V plate 13 is formed a cam 19, which normally engages a'roller 20 whichis pinned at 21 to a lever 22. This lever is fulcrumed at- 23 and the roller is held against the cam'by means of spring 2 1. In Fig. 3 I have shown a modification in whicha vlatch means is.

In theoperation of starting, the latch 25 is released as shown in Fig. 3 in those models 8' in which a latch is used, and the roller allowed to contact with the cam. As the driving shaft is now turned, the pin17 revolving with the face plate 14 pulls the pin 15 and hence this plate 13 and driven shaft .11 around with it. When the cam 19, however, strikes the roller 20 the cam and the driven shaft will be temporarily stopped owing to- .the stiffness of the spring 24:; the pin 15' therefore being at a standstill while the pin I 17 revolves, will cause the spring 18 to be stretched until a tension is reached therein that will be able to overcome the pressure of the spring 24:, at which time the cam will be suddenly released and the armature shaftll if will be caused to rotate for a fractionofa revolution at highspeed. 'If the spring 18.

fails for anyreason to move the cam 19 over j the roller 20'the end of the slot 16 will strike the pin 15 and positively release the cam. At

the instant of release the roller 20 acting on 9 5 g the rear face of the cam will greatly accele erate the motion of the cam. V This snap action is so timed as to correspond with the point of ignition ofthe engine with which 1 it is connected. As a result the spark pro duced by the magneto is as'powerful as that which would be producedif theengine were running at a very high rate of speed.

After the engine is in operation and has" I attained a considerable speed, the roller 20 may be held out of contact with the cam by means of the lever 22, or a means, such as.

of my invention, it is to be understood that others are possible. I desire therefore that it shall be understood that other changes in the construction and arrangement of parts may be made Without departing from the spirit and scope of the invention as covered by the appended claims: 7

1. In a driving means, a driving shaft and a driven shaft, yieldable means connecting the two shafts, a projection carried by the driven shaft and a spring pressed roller adapted to engage the projection.

2. In a driving means, a driving shaft and a driven shaft, yieldable means connecting the two shafts, a projection carried by the driven shaft, a spring pressed roller adapted to engage the projection, and means for holding the roller out of engagement.

3. In a driving means, a driving shaft and a driven shaft, yieldable means connecting the two shafts, and a spring pressed roller adapted to engage a projection on the driven shaft first to retard and then to accelerate the driven shaft. v

4:. In an impulse starter, a driving shaft and a driven shaft, a cam on the driven member and a driven member substantially in alignment, a yieldable driving connection between the members, a cam on the driven member having front and rear faces, and means in the path of the cam adapted to engage the front face to retard the driven member and to engage the rear face to accelerate the driven member.

6. In a driving mechanism, a driving member and a driven member yieldably connected together, a cam on the driven member having two inclined faces, means adapted to engage one face ofthe cam toretard the driven member and to engage the other face to accelerate the driven member, and means for moving the first named means out of the path of the cam. I

In testimony whereof I afiiX my signature.

F. D. HOWE. 

